derkom wrote:Quick question for you: Can you tell me what your jumper settings are for these jumpers both next to the TOS ROMs and in between the TOS ROMs and the RAM?
mikro wrote:I'm pretty confident those are ROM wait states settings, similar to what you have on Falcon on the far left of the PCB
derkom wrote:But now I have hope for RGB working better than VGA.
calimero wrote:you receive only Sparrow motherboards, without case?
I was wonder what kind of badged (label) does Sparrow had...?
Is FX-1 from Sparrow?
calimero wrote:So yours and Mikros Sparrow are essentially the same?
calimero wrote:Mikro, please put yours photos and serial numbers of Sparrow in database: http://milan.kovac.cc/atari/chipmunk/
derkom wrote:But it was only today that I noticed mikro's board has a bunch of stuff around the expansion connector that my board lacks. Too bad.
troed wrote:Too low res picture to see clearly, but that looks like stuff that should be possible to source.
czietz wrote:Judging from the components missing (two crystals, two diodes, some transistors), I suspect this is the "famous" PLL to lock the system clock to the PAL color frequency. It is present in all Ataris with a PAL modulator -- starting with the 520STM. See it here in the Falcon schematic: https://www.dev-docs.org/docs/htm/searc ... 28Rev+G%29, page 2, the block annotated "stuffed in PAL systems only". derkom's Sparrow is a "non-PAL" model and hence has the crystal oscillator that is missing in mikro's machine.
As for the things in the output circuitry: mikro's has a modulator, derkom's hasn't. Hence only the transistor and diodes to generate composite sync, much like in the ST.
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